Some of these collections include secondary and reference sources:
Many historical materials (newspapers, reports, etc.) remain accessible only in "microform" -- the generic term for microfilm and other micro-photographic technologies that became popular for preserving historical materials in the middle of the 20th c., and which remain in use today. Below are links to some materials that may be of interest. To access these materials, write to askyalelibrary@yale.edu and include the link to the catalog record and any specific notes on which reels you would like to consult (e.g., reel numbers, years of publication). Library staff will retrieve the reels and place them on hold for you in Bass Library, where staff will also be available to assist you with using the microform readers that are currently located there:
Link to website where PDFs of many of the microfilm guides for these collections can be found and accessed.